The main failure of flight controllers in the field is letting "FOD" enter or get on the FC, something ferrous/magnetic get sucked inside and cause a short. They can even be attracted by magnetic attraction force. This heat shrink can greatly reduce the risk of damage.
This size will fit most 35x35 Flight controllers, and most of the AIO controllers.
will also fit:WRAITH32 V1.1 4IN1 ESC 4X35A
will NOT fit:
1 Order: Will cover around 3 Flight controllers